Sample 95MW0107 is an unfoliated granite with a
composition of K-feldspar (58%), quartz (20%), plagioclase (15%),
muscovite (2%), biotite (1%), epidote (1%), oxides (1%), chlorite (1%),
and trace sphene. K-feldspar occurs mainly as large (up to 8 mm),
perthitic, tartan twinned porphyries with irregular grain boundaries.
Quartz is found in the matrix and in ~3-mm aggregates. Plagioclase
grains, generally smaller than K-feldspar porphyries, show albite
twinning, seritization, and differential recrystallization. Biotite
occurs in bundles, and it is extensively altered to chlorite and epidote.
Microcrystalline sphene rims some oxide grains. |